5a9k: Difference between revisions
New page: '''Unreleased structure''' The entry 5a9k is ON HOLD Authors: Chaban, Y., Stead, J.A., Ryzhenkova, K., Whelan, F., Lamber, K., Antson, F., Sanders, C.M., Orlova, E.V. Description: Stru... |
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The entry | ==Structural basis for DNA strand separation by a hexameric replicative helicase== | ||
<SX load='5a9k' size='340' side='right' viewer='molstar' caption='[[5a9k]], [[Resolution|resolution]] 19.00Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[5a9k]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Bovine_papillomavirus Bovine papillomavirus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5A9K OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5A9K FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 19Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene></td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=5a9k FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5a9k OCA], [https://pdbe.org/5a9k PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5a9k RCSB], [https://www.ebi.ac.uk/pdbsum/5a9k PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5a9k ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/VE1_BPV1 VE1_BPV1] ATP-dependent DNA helicase required for initiation of viral DNA replication. It forms a complex with the viral E2 protein. The E1-E2 complex binds to the replication origin which contains binding sites for both proteins. | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Hexameric helicases are processive DNA unwinding machines but how they engage with a replication fork during unwinding is unknown. Using electron microscopy and single particle analysis we determined structures of the intact hexameric helicase E1 from papillomavirus and two complexes of E1 bound to a DNA replication fork end-labelled with protein tags. By labelling a DNA replication fork with streptavidin (dsDNA end) and Fab (5' ssDNA) we located the positions of these labels on the helicase surface, showing that at least 10 bp of dsDNA enter the E1 helicase via a side tunnel. In the currently accepted 'steric exclusion' model for dsDNA unwinding, the active 3' ssDNA strand is pulled through a central tunnel of the helicase motor domain as the dsDNA strands are wedged apart outside the protein assembly. Our structural observations together with nuclease footprinting assays indicate otherwise: strand separation is taking place inside E1 in a chamber above the helicase domain and the 5' passive ssDNA strands exits the assembly through a separate tunnel opposite to the dsDNA entry point. Our data therefore suggest an alternative to the current general model for DNA unwinding by hexameric helicases. | |||
Structural basis for DNA strand separation by a hexameric replicative helicase.,Chaban Y, Stead JA, Ryzhenkova K, Whelan F, Lamber EP, Antson A, Sanders CM, Orlova EV Nucleic Acids Res. 2015 Aug 3. pii: gkv778. PMID:26240379<ref>PMID:26240379</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
[[Category: | </div> | ||
[[Category: | <div class="pdbe-citations 5a9k" style="background-color:#fffaf0;"></div> | ||
[[Category: | |||
[[Category: | ==See Also== | ||
[[Category: Orlova | *[[Helicase 3D structures|Helicase 3D structures]] | ||
[[Category: | *[[Replication protein E1|Replication protein E1]] | ||
[[Category: | == References == | ||
[[Category: Stead | <references/> | ||
[[Category: | __TOC__ | ||
</SX> | |||
[[Category: Bovine papillomavirus]] | |||
[[Category: Large Structures]] | |||
[[Category: Antson F]] | |||
[[Category: Chaban Y]] | |||
[[Category: Lamber K]] | |||
[[Category: Orlova EV]] | |||
[[Category: Ryzhenkova K]] | |||
[[Category: Sanders CM]] | |||
[[Category: Stead JA]] | |||
[[Category: Whelan F]] | |||